The service has been down for more than two hours as there seems to be an issue with the ‘feed delivery’, and some mobile users are complaining that they cannot view any new photos on their feeds. There are also some users who are not able to login to the app. Last month the photo sharing service revealed that it now had nearly 200 million monthly active users. The Facebook-owned company also revealed that users had shared more than 20 billion photos to date. While the company is working on fixing the issue, users have taken to Twitter to vent their frustrations.